Design of LSI speech spectrum analyzer using switched capacitor filter techniques

This paper presents a design approach to an LSI speech spectrum analyzer, which constructs one board speech recognition systems with other LSIs[4]. Particularly, the purpose of this LSI speech spectrum analyzer is to achieve high performances, such as a high resolution filter bank, powerful interface to CPU and variable spectrum integration intervals. In order to realize the above spectrum analyzer on one chip, switched capacitor filter (SCF) techniques are applied to filter bank synthesis. Design techniques to considerably reduce a SCF´s area are introduced. A breadboard model constructed with discrete components shows good filter performances and high speech recognition rates. It is recognized through LSI design that this LSI can be realized on a 42 mm²chip with power dissipation of about 300 mW using the latest CMOS technology.